It's the DTV card that must be activated within the time limit. Are you sure your apartment complex forces you to use their card? They shouldn't care. Whether you use a new card or swap an existing card, DirecTV (or some reseller) must be contacted to activate the exact receiver/card combination that you will be using. You can't just swap a card from one receiver to another without contacting DirecTV (excepting hacking).

This requirement to activate the included card is typical for newly purchased DirecTV receivers so if your apartment complex really is unyielding about this they are preventing everyone from buying their own receiver without paying hundreds of dollars in fees. (Maybe that is their goal. Do they charge a rental fee or something like that for the hardware?)

-Dylan